Simple control strategy for inverter-based distributed generator to enhance microgrid stability in the presence of induction motor loads

Owing to the increasing penetration of decentralised generation, stable islanded microgrid operation is essential. Fault provoked islanding conditions may lead to unstable microgrid operation, particularly when direct connected induction motor (IM) loads are included. This study proposes a control strategy for inverter-based DG to support microgrid stability. A transient control mode (TCM), based on droop design and flow management of current components is proposed to enable the microgrid to withstand transient faults and resume stable islanded operation. The microgrid model, which includes a mix of synchronous generation, inverter-based DG and IM loads, has been simulated in Matlab. Results show that inverter control schemes supported with TCM can withstand longer fault durations. Inverter current control scheme equipped with TCM gives better stability performance for the microgrid with IM loads.